Clinical and Radiological Phenotypes and Endotypes

Prediction of Clinical Bronchiectasis from Asymptomatic Radiological Bronchiectasis

Background

Under persistent inflammation, asymptomatic radiological bronchiectasis (ARB) may develop into clinical bronchiectasis (CB). Although CB has been extensively studied, the potential for ARB to evolve into CB remains largely unexplored. Whether the ARB could progress to CB and the risk factors to speed up the process are poorly understood.

Methods

This was an observational cohort study. 370 patients with radiological bronchiectasis were included in Wuhan Union Hospital in 2018. 296 ARB patients were followed up in 2022 to verify if they progressed to CB and divided the development and validation of clinical prediction models into a training set (n=207) and a validation set (n=89) by the ratio of 7:3. LASSO algorithm and multivariable logistic regression analysis were performed to construct a new nomogram model. ROC, a calibration and decision curve were used to assess the predictive performance of our new prediction model.

Results

370 patients (74, 20% with CB) were finally included. Compared with ARB, CB had lower BMI, Bhalla score, FEV1% predicted, greater extent and degree of bronchodilation, more lobes with mucus plugs, greater thickness of bronchodilation, greater likelihood of pulmonary heart disease and chronic obstructive pulmonary disease (COPD), and lower likelihood of hypertension and coronary artery disease (P<0.05). In 2022, 60 out of 296 ARB patients progressed to CB. Age, FEV1% predicted, COPD, heart failure (HF), degree of bronchiectasis, number of lobes with bronchiectasis and number of lung segments with mucus plugs were risk factors. The AUCs of the prediction model were 0.866 (95% CI, 0.802-0.931) in the training set and 0.860 (95% CI, 0.770-0.949) in the validation set.

Conclusion

ARB may progress to CB under the risk factors, including age, FEV1% predicted, COPD, HF and CT images including degree of bronchiectasis, number of lobes with bronchiectasis and number of lung segments with mucus plugs), based on which the nomogram model is a convenient and efficient tool for follow-up management and preventing CB in patients with ARB.

Neutrophilic inflammation in bronchiectasis

Noncystic fibrosis bronchiectasis, hereafter referred to as bronchiectasis, is a chronic, progressive lung disease that can affect people of all ages. Patients with clinically significant bronchiectasis have chronic cough and sputum production, as well as recurrent respiratory infections, fatigue and impaired health-related quality of life. The pathophysiology of bronchiectasis has been described as a vicious vortex of chronic inflammation, recurring airway infection, impaired mucociliary clearance and progressive lung damage that promotes the development and progression of the disease. This review describes the pivotal role of neutrophil-driven inflammation in the pathogenesis and progression of bronchiectasis. Delayed neutrophil apoptosis and increased necrosis enhance dysregulated inflammation in bronchiectasis and failure to resolve this contributes to chronic, sustained inflammation. The excessive release of neutrophil serine proteases, such as neutrophil elastase, cathepsin G and proteinase 3, promotes a protease-antiprotease imbalance that correlates with increased inflammation in bronchiectasis and contributes to disease progression. While there are currently no licensed therapies to treat bronchiectasis, this review will explore the evolving evidence for neutrophilic inflammation as a novel treatment target with meaningful clinical benefits.

The role of radiological imaging in the management of severe and difficult-to-treat asthma

Radiological imaging has proven to be a useful tool in the assessment of asthma, its comorbidities and potential complications. Characteristic chest radiograph and computed tomography scan findings can be seen in asthma and in other conditions that can coexist with or be misdiagnosed as asthma, including chronic rhinosinusitis, inducible laryngeal obstruction, excessive dynamic airway collapse, tracheobronchomalacia, concomitant COPD, bronchiectasis, allergic bronchopulmonary aspergillosis, eosinophilic granulomatosis with polyangiitis, and eosinophilic pneumonia. The identification of the characteristic radiological findings of these conditions is often essential in making the correct diagnosis and provision of appropriate management and treatment. Furthermore, radiological imaging modalities can be used to monitor response to therapy.

Endotypes in bronchiectasis: moving towards precision medicine. A narrative review

Bronchiectasis is a highly complex entity that can be very challenging to investigate and manage. Patients are diverse in their aetiology, symptoms, risk of complications and outcomes. "Endotypes"- subtypes of disease with distinct biological mechanisms, has been proposed as a means of better managing bronchiectasis. This review discusses the emerging field of endotyping in bronchiectasis. We searched PubMed and Google Scholar for randomized controlled trials (RCT), observational studies, systematic reviews and meta-analysis published from inception until October 2022, using the terms: "bronchiectasis", "endotypes", "biomarkers", "microbiome" and "inflammation". Exclusion criteria included commentaries and non-English language articles as well as case reports. Duplicate articles between databases were initially identified and appropriately excluded. Studies identified suggest that it is possible to classify bronchiectasis patients into multiple endotypes deriving from their co-morbidities or underlying causes to complex infective or inflammatory endotypes. Specific biomarkers closely related to a particular endotype might be used to determine response to treatment and prognosis. The most clearly defined examples of endotypes in bronchiectasis are the underlying causes such as immunodeficiency or allergic bronchopulmonary aspergillosis where the underlying causes are clearly related to a specific treatment. The heterogeneity of bronchiectasis extends, however, far beyond aetiology and it is now possible to identify subtypes of disease based on inflammatory mechanisms such airway neutrophil extracellular traps and eosinophilia. In future biomarkers of host response and infection, including the microbiome may be useful to guide treatments and to increase the success of randomized trials. Advances in the understanding the inflammatory pathways, microbiome, and genetics in bronchiectasis are key to move towards a personalized medicine in bronchiectasis.

Diagnosis and management of non-cystic fibrosis bronchiectasis

Bronchiectasis is a heterogeneous and increasingly prevalent chronic pulmonary disease that is associated with significant morbidity. In this review, we outline how patients with bronchiectasis may present clinically and describe an approach to its diagnosis, including how to identify an underlying aetiology. We discuss the important considerations when treating either acute exacerbations or stable disease and provide an overview of the role of long-term antimicrobials, airway clearance methods and other supportive management.

Developing a diagnostic bundle for bronchiectasis in South Korea: A modified Delphi Consensus Study

Background

A diagnostic bundle for bronchiectasis in South Korea is necessary because the etiologies of bronchiectasis and related diseases vary significantly among different regions and ethnicities.

Methods

A modified Delphi method was used to develop expert consensus statements on a diagnostic bundle for bronchiectasis in South Korea. Initial statements proposed by a core panel, based on international bronchiectasis guidelines, were discussed over one online meeting and two email surveys by a panel of experts (≥70% agreement).

Results

Twenty-one experts participated in the study, and 30 statements on a diagnostic bundle for bronchiectasis were classified as recommended, conditional, or not recommended. The expert panel agreed that 1) a standardized diagnostic bundle is useful in clinical practice, 2) diagnostic tests for specific diseases, including immunodeficiency and allergic bronchopulmonary aspergillosis, are necessary when clinically suspected, 3) initial diagnostic tests, including sputum microbiology and spirometry, are essential in all bronchiectasis patients, and 4) patients should be referred to specialized centers when rare causes such as primary ciliary dyskinesia are suspected.

Conclusion

In this Delphi survey, expert consensus statements were generated on which specific diagnostic, laboratory, microbiologic, and pulmonary function tests to obtain when managing patients with bronchiectasis in South Korea.